kevin campbell, practicing cardiologist and assistant professor of medicine at the university of north carolina. so how exactly could our bodies fight off cancer like we fight off the common cold? >> there's certain immune cells in our body that attack viral infections like the common cold. these cells are called t cells and what happens in this particular situation in this experiment we've talked about today is we pull the t-cells out of the body of a patient with cancer. we use gene therapy to make them attack the cancer cells and put them back to fight the cancer. jenna: 21 young people received this treatment, 18 of them are in remission. could this be a cure for cancer? >> i think that this may be well on the way to curing diseases like cancer. i think of it as personalized medicine. we're using your genetic material to fight off this particular cancer. this was done in leukemias and in some children, they're seeing no cancer at three years. not everyone but the results are very promising. jenna: they also tried in adults. 37 adults with leukemia, 12 went into complete remission,